title: Brain-gut interactions between central vagal activation and abdominal surgery to influence gastric myenteric ganglia Fos expression in rats.
abstract: We previously showed that medullary thyrotropin-releasing hormone (TRH) or the stable TRH agonist, RX-77368 administered intracisternally induces vagal-dependent activation of gastric myenteric neurons and prevents post surgery-induced delayed gastric emptying in rats. We investigated whether abdominal surgery alters intracisternal (ic) RX-77368 (50 ng)-induced gastric myenteric neuron activation. Under 10 min enflurane anesthesia, rats underwent an ic injection of saline or RX-77368 followed by a laparotomy and a 1-min cecal palpation, or no surgery and were euthanized 90 min later. Longitudinal muscle/myenteric plexus whole-mount preparations of gastric corpus and antrum were processed for immunohistochemical detection of Fos alone or double labeled with protein gene-product 9.5 (PGP 9.5) and vesicular acetylcholine transporter (VAChT). In the non surgery groups, ic RX-77368 induced a 17 fold increase in Fos-expression in both gastric antrum and corpus myenteric neurons compared to saline injected rats. PGP 9.5 ascertained the neuronal identity of myenteric cells expressing Fos. In the abdominal surgery groups, ic RX-77368 induced a significant increase in Fos-expression in both the corpus and antrum myenteric ganglia compared with ic saline injected rats which has no Fos in the gastric myenteric ganglia. However, the response was reduced by 73-78% compared with that induced by ic RX 77368 without surgery. Abundant VAChT positive nerve fibers were present around Fos positive neurons. These results indicate a bidirectional interaction between central vagal stimulation of gastric myenteric neurons and abdominal surgery. The modulation of gastric vagus-myenteric neuron activity could play an important role in the recovery phase of postoperative gastric ileus.
authors.affiliation: CURE/Digestive Diseases Research Center, Center for Neurobiology of Stress, Department of Medicine, Digestive Diseases Division at the University of California Los Angeles, and VA Greater Los Angeles Health Care System, CA 90073, USA.
authors.forename: Marcel
authors.initials: M
authors.lastname: Miampamba
authors.forename: Mulugeta
authors.initials: M
authors.lastname: Million
authors.forename: Yvette
authors.initials: Y
authors.lastname: Taché
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D007150:Immunohistochemistry; D008297:Male; D009197:Myenteric Plexus / Q000187:drug effects* / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013270:Stomach / Q000187:drug effects / Q000294:innervation*; D013973:Thyrotropin-Releasing Hormone / Q000031:analogs & derivatives / Q000494:pharmacology; D014630:Vagus Nerve / Q000187:drug effects / Q000378:metabolism
chemical_list: D016760:Proto-Oncogene Proteins c-fos; D013973:Thyrotropin-Releasing Hormone; C027979:L-pyroglutamyl-L-histidyl-3,3-dimethylprolinamide; D011761:Pyrrolidonecarboxylic Acid